Engineering Commons^™

Hardware And Software Study Of Active Noise Cancellation, Riggi Aquino, Jacob Lincoln

Electrical Engineering

Noise cancellation involves removing an unwanted noise while keeping the source sound. The source sound may consist of speech, music played from a device such as an iPod or a computer, or no sound at all. The objective of this project is to study the process of noise cancellation both as hardware and as software. The hardware will consist of building a noise cancelling circuit that uses headphones as an output, a microphone to pick up the noise to be cancelled and, if desired, a source sound. The software portion of the experiment will use MATLAB to simulate the hardware …

Retrofitting A Car Alternator For Low-Speed Power Generation, Yuri Carrillo

Electrical Engineering

This report presents the analysis and methods taken to appropriately modify a car alternator to operate as a low speed generator for wind or hydro power generation. A Toyota car alternator taken from a junkyard is characterized via an Open-Circuit test to evaluate its operating specifications. The car alternator is also measured to determine its physical dimensions. The acquired values are used with the generated voltage equation to determine the machine’s unknown rotor values— the product of the rotor winding factor and the number of rotor windings (kfNf). Using the generated voltage equation with the determined machine parameters, the number …

High Efficiency Audio Amplifier, Grant Moore

Electrical Engineering

This project combines the advantages of high efficiency of power electronics with the existing high fidelity of audio amplifiers. The result will be functionally equivalent to existing amplifiers but will use considerably less energy. A complete system was designed, simulated, built and tested in a period of three quarters. The end result is an amplifier that functions, but would not be suitable for commercial marketing. Suggestions to improve the performance are provided.

An Overview Of Binary Arithmetic Architectures & Their Implementation In Dsp Systems, Joseph Waddell

Electrical Engineering

This project gives looks at different binary adder and multiplier architectures and how they are implemented in a DSP system as a digital filter. Testing is performed in the Digilent Nexys2 FPA board and filters are implemented using various realizations including normal direct form I and cascade direct forms I and II. Signal filtering is performed in real time at various frequencies and results are provided on an oscilloscope and with a stereo speaker.

"Auto-Tuned" Stereo, Daniel Montes

Electrical Engineering

The purpose of this project is to determine the capability of introducing delay and gain to audio signals to synthesize a “tuned” experience. The project uses audio operational amplifiers, field effect transistors, a class D amplifier, microphones, speakers, a 32-bit microcontroller for design and testing. When implementing the MOSFET into the all pass filter, the phase delay occurs by varying the transistor resulted in minimal change in phase. MOSFETs are used as variable resistors to vary the phase change and gain. By modifying the gain the synthesized distance from each speaker can be adjusted. Varying the phase change provides the …

Lyfi, Kianoosh Salami, Justin Cotton, Elush Shirazpour

Electrical Engineering

This paper will cover the steps necessary to design, build, and manage networkable smart light switches over WiFi via a mobile application. It contains a microcontroller running a real time operating system, a WiFi module, a Java server with SQLite databasing, and a mobile phone application.

LyFi is designed to turn on/off and dim household lights while only requiring the same installation procedure as a less capable dimmer switch. Once installed and connected to a network, LyFi will self-discover and configure. The server automatically propogates a database of nodes where any mobile device running an application can receive an updated …

Independent Moisture-Sensitive Automatic Watering System, Jessica Sherbon

Electrical Engineering

With the availability of home improvement supplies, plant owners can quickly and easily set up an automatic system that waters their gardens based on a specified schedule. However, most of these systems require an electric outlet or water faucet making them unusable in locations where installed water and power lines do not exist, such as apartment balconies. This project defines a small-scale automated watering system that runs independently of installed water and power lines. The system takes water from a reservoir, such as a tank or bucket, and supplies that water to individual plants via a drip system. The design …

Inductive Metal Identification, Paul Maggi

Electrical Engineering

This project focuses on creating a device to differentiate between various types of metals via magnetic induction. Magnetic induction is used because it is both non-optical and non-contact. It achieves this by generating a varying magnetic field, which induces eddy currents in the metal. These eddy currents produce small disturbances in the surrounding magnetic field, which can be sensed with Hall Effect Sensors (HES). The primary challenge in this project was generating a sufficiently strong magnetic field to detectable disturbances. In order to achieve better results, a stronger magnetic field must be used as well as more sensitive Hall Effect …

Gamecube To Nintendo 64 Controller Converter, Andrew Jia-Haur Lee

Electrical Engineering

No abstract provided.

Portable Solar Powered Charging Station, Jordan Bonner

Electrical Engineering

The portable solar powered charging station uses a solar powered mat that can be folded for portability. The device has the ability to charge small electronics during both day and night. When sunlight is available, the charger charges two C batteries in series and at the same time it charges any electronic device that can be connected via USB or cigarette lighter. At night the charger will charge the same electronic devices from the onboard batteries. The charging station must be able to interface with electronic devices using USB and a car cigarette lighter to charge the device’s battery.

Digital Guitar Effects Unit And Amplifier, Kevin Salvador

Electrical Engineering

This report outlines the design and implementation of a digital guitar effects unit and amplifier. The main portion of this project consisted of the digital equalizer and effects. Several commercial equalizers were researched in order to decide the typical frequency bands and average amount of bands total. Eventually 8 bands were selected. A range of approximately 20Hz-3kHz was chosen based on test data of guitar signals. Popular effects that were incorporated in this project include Distortion, Echo, Reverb, Chorus and Flanger. The digital processor chosen was a Texas Instruments c6713 floating point processor. Designs for the various filters were done …

Multipolymer Interactions In Bulk Heterojunction Photovoltaic Devices, Grant Olson

Physics

Multipolymer photovoltaics, single layer devices made up of multiple photoactive polymers, can create organic photovoltaics (OPVs) with a wider spectral response than single polymer systems without the difficult fabrication of a tandem. Our group has successfully created multipolymer solar devices with 2% power conversion efficiency. We have analyzed the optical and electrical properties of these devices, and found that it may be possible for polymers to assist each other with charge extraction, though combining polymers disrupts single polymer crystallinity.

The Hovering Ball Exhibit, Matthew Bauzon, Will Lennox, Michelle Swan

Mechanical Engineering

No abstract provided.

Quantifying Proximal Conformability Of A Thoracic Aortic Stent Graft, Dylan Reinsdorf, Kendall Smith

Mechanical Engineering

This report is documentation of a Senior Project completed by Dylan Reinsdorf and Kendall Smith, in partial fulfillment of a Bachelor of Science in Mechanical Engineering at Cal Poly, San Luis Obispo. Medtronic Inc. approached the team with a need to quantify proximal conformity of stent grafts in the thoracic aorta. A solution was designed that included an aorta model that simulates clinical conditions, and a measurement method for stent graft conformability. This report documents all phases of the project, from sponsor requirements to final design to product realization and testing.

Innovative Cargo Rack Solutions, Travis Mccart, Brian Blummer, Whit Ratcliff

Mechanical Engineering

This report describes the process of designing, building, and testing a lowering mechanism for a roof-mounted SUV cargo box. It provides a detailed problem description and a specific list of requirements that our design must comply with. Existing products and concepts are presented which meet one or more of our design requirements. Six design concepts are discussed and down-selected to three for further development. A final design has been chosen and described in detail. A team management plan is included to specify member responsibilities and a schedule details major deadlines and goals. Manufacturing processes and testing procedures are described in …

Design Of A Human Powered Helicopter Airframe, Sheen Kao, Daniel Layton, Philip Sobol

Mechanical Engineering

In 1989 Cal Poly’s Da Vinci III was the first human powered helicopter (HPH) to achieve flight; our goal is to research and develop a new airframe for the next generation Da Vinci. This report outlines a brief history of human powered flight and details a method of constructing for the airframe. An optimized airframe geometry was also researched and is explained in detail.

Formula Hybrid Drivetrain Design, Zachary (Zak) Mcfarland, Alex Pruitt, William Domhart

Mechanical Engineering

The Formula Hybrid senior project group was tasked with designing and building a drivetrain system for the Cal Poly Society of Automotive Engineers (SAE) Formula Hybrid (FHSAE) team. FHSAE gave customer requirements for performance and geometry for the drivetrain and the FHSAE rulebook has guidelines regarding safety requirements. The team chose to compete in the electric category of the 2012 FHSAE competition. After getting feedback from previous car performance and researching different powertrain options, the senior project team arrived at three conceptual ideas. Using a quality function deployment method, the senior project team chose the concept where two motors independently …

Throwing Frame For Athletes With Dissabilities, Andrew Higgins, Stefan Owechko, Gabriel (Gabe) Terrasas, Kevin Crisfield

Mechanical Engineering

Team Zeus’ senior project was to design, build and test a working throwing frame system for Bridge II Sports, a nonprofit organization in North Carolina. The throwing frame is used to allow athletes and individuals with disabilities to throw shot-put, discus, and javelin using a frame to sit against. Team Zeus was specifically tasked to build a frame that is lighter weight and more transportable than products that are currently on the market. This frame also is adjustable to accommodate a wide range of athlete weights, sizes, and abilities. The final result is a 35lb aluminum frame with two different …

Senior Project #7: Longboard Test Apparatus, Derek Chan, Colin Harris, Nico Lee

Mechanical Engineering

The aim of this project is to create a machine that will test longboards made by Method Sports and Freebord. Through analysis and many iterations, Board Busters has assembled a design to fulfill the requirements set forth by these companies, who also sponsor the project. Through use of a four-bar, frame, and two spinning disks, the machine will accurately simulate riding conditions seen by a board in use by customers, allowing the sponsoring companies to improve designs and verify warranties.

Recreational Nordic Sit Ski, Mathew Bissonnette, Johnathon Gorski, Kevin Izumiya

Mechanical Engineering

The purpose of this project was to design, build, and test a recreational Nordic sit ski for use by Disabled Sports Eastern Sierra. The goal was to improve adjustability and reduce weight compared to previous sit ski designs. The project was completed by Cal Poly Mechanical Engineering seniors Mathew Bissonnette, Johnathon Gorski, and Kevin Izumiya. Kinesiology seniors Harpreet Saini and Carl Anderson provided discipline support and disability etiquette training.

The project was sponsored by the National Science Foundation Research to Aid Persons with Disabilities (RAPD) grant. The grant was proposed by and awarded to Dr. Brian Self and Dr. James …

Thermocouple Calibration Device, Angelica M. Larios, Cameron D. Peck, Andrew J. Smith

Mechanical Engineering

The goal of this project is to develop a thermocouple calibration unit with a high degree of confidence and accuracy. This thermocouple calibration device will be designed and developed at Cal Poly San Luis Obispo and delivered to Tesla Motors Inc.

To best utilize thermocouples, they must be calibrated to a known accuracy. Non-commercially produced thermocouples have unknown accuracies. The final deliverable will be a semi-automated device that produces a calibration curve for each thermocouple with a known confidence and accuracy.

Creating A Solar Cell Array From A Single Silicon Wafer, Samyukta Gade, Roderick Marstell

Materials Engineering

Two different processes to create multi-celled solar panels from single wafers were made and implemented. To do this, the cells must not have a common ground, and both designs use different approaches to solve this problem. One utilizes a 2.9 µm deep n-type well within a 10.74 µm deep p-type well in an n-type wafer. There are two cells in series, which has a theoretical voltage of 1 V. The cells are connected in series with 1.9 µm thick gold traces. Any area that the gold is not in contact with the silicon has a .5 µm layer silicon dioxide …

The Effects Of Concentration, Stir Rate, And Processing Temperature On The Iridescence Of Polymethyl Methacrylate Nanoparticles, David Baruela

Materials Engineering

Synthetic opals were synthesized by creating polymethyl methacrylate (PMMA) nanospheres in order to determine which conditions would create the best iridescent samples. The factors affecting the iridescence were nanosphere concentration, stir rate, and processing temperature. PMMA solutions were made by adding 17 mg of granular azobis to a solution of 16 mL of distilled water with 3 mL of methyl methacrylate (MMA). The solution was stirred at different rates, slow and fast, and different temperatures, 70 °C and 90 °C, under a constant flow of nitrogen gas for 40 minutes until the polymerization reaction was complete. Glass substrates were prepared …

Fabricating Replacement Glass Prisms For The Piedras Blancas Lighthouse, Daniel Garcken

Materials Engineering

The objective of this project was to design and create a process for manufacturing replacement glass prisms for the Piedras Blancas lighthouse and several other lighthouses nationwide. The prisms were designed to be in multiple metal arrays spread across the floor of the beacon room (the topmost room of the lighthouses). The prisms functioned to transmit extra, radiant light from the beacon light through the floor of the beacon room and disperse it into the maintenance room below. Using computer aided drafting (CAD) software, an original prism was measured and modeled; the corresponding mold was also modeled. G-codes for controlling …

Effects Of Abrasive Particles On The Projected Fatigue Life Of Nylon Climbing Rope, Casey Johnson, Charlie Klonowski

Materials Engineering

When climbing rope is used outdoors, it is exposed to foreign particles such as sand and silt. These particles can potentially work their way through a rope’s sheath and damage the load bearing core decreasing the rope’s strength without exhibiting obvious wear. This project quantified the effect of abrasive particles on the fatigue life of nylon climbing rope. The experimental design involved 18 pieces of static nylon rope of kernmantle construction. 9 of these samples were heavy agitated in a slurry of water, silt, sand and soil, and left to sit for 24 hours. The remaining 9 samples were submerged …

Synthesis Of White Cadmium-Selenium Quantum Dots, Kyle Reilly

Materials Engineering

A process was developed for the synthesis of cadmium-selenium quantum dots that fluoresce at multiple wavelengths, giving a white color to the solution. The process involved making a selenium pre-cursor, then a cadmium precursor, then injecting the selenium precursor into the cadmium precursor and extracting a sample. Once the a repeatable process for synthesizing white quantum dots was developed, the absorption and fluorescence was measured and recorded over a period of two weeks. In the development of the process, the key variables were the temperature of the cadmium precursor and the time between injecting the selenium precursor and extracting the …

Characterization Of Positive Macrosegregation At The Subsurface Of Direct-Chill Cast 7050 Aluminum Forging Billets, Aaron Youril

Materials Engineering

Segregation of alloying elements during casting of forging billets may persist to the final forged component leading to unacceptable surface appearance. Determination of the elements or compounds that segregate is the essential first step to solving this problem. Differential Scanning Calorimetry (DSC) was used to determine a composition profile of the macrosegregation occurring at the subsurface of an as-cast 7050 aluminum alloy billet. Data collection was carried out by separating 10 to 20 mg samples from the outer centimeter along the radius of the billet, as well as samples from the bulk interior of the billet for comparison with the …

Analysis Of Failed Forging Saddling Mandrels And Process Improvements For Increased Mandrel Lifespan, Brock Costalupes

Materials Engineering

This project seeks to increase the lifespan of steel mandrels used by Schlosser Forge in the saddling process, which is part of the production of forged rings for the aerospace and power generation industries. All saddle mandrel samples were taken from used 4340 steel mandrels. Hardness profiles were measured across rectangular bars cut from the transverse direction of a completely fractured piece of a 7″ diameter mandrel. The hardness near one outer surface of the tested bar was 36 HRC and gradually decreased to 30.5 HRC at the opposite surface. Macroscopic examination of the primary fracture surface along with light …

Effect Of Heating Temperature, Heating Time And Initial Microstructure On Recrystallization Of Waspaloy During Heating For Forging, Marissa Hill

Materials Engineering

A fine, uniform grain size is required for creep limited Waspaloy in aircraft engine applications. Upon heating, Waspaloy does not always recrystallize in a uniform manner resulting in occasional large grains with a majority of the grains meeting the grain size requirements. Waspaloy’s microstructure was analyzed with different heat treatments and in the as-forged condition. The strengthening mechanism is the gamma prime phase. The gamma prime solvus temperature is 1908°F so the different heat treatments were determined around that temperature, as well as the forging temperature range of 1800-2150°F. At the 1850°F heat treatment, the microstructure recrystallized with small grains, …

Real World Computer Forensics, Jessica Riccio

Liberal Arts and Engineering Studies

No abstract provided.